Answer:
V=144
Step-by-step explanation:
To find the volume of a pyramid, use the formula V=B•h, B being the base and h the height. So 12•12=144.
(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes
(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)
Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes
(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%
With actual average time to walk to the bus stop being 10 minutes;
(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes
(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.
(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0
From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%
Steps to solve:
47.5 + 4.5x ≤ 65
~Subtract 47.5 to both sides
4.5x ≤ 17.5
~Divide 4.5 to both sides
x ≤ 3.8888888889...
So, yes, the friends will have to share snacks.
Best of Luck!
Answer:
d. H0: 
vs. 
Step-by-step explanation:
A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".
The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".
The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".
On this case the Management try to determine if there is a difference in the average investment/quad between using electricity and using gas. So this needs to be on the alternative hypothesis. And the complement of the alternative hypothesis would be on the null hypothesis.
Null hypothesis :
Alternative hypothesis: 
Or equivalently:
Null hypothesis :
Alternative hypothesis: 
Other important thing is that on the alternative hypothesis we never can have the symbol equal.
So on this case the best options is:
d. H0: vs.
